Research has provided support for the efficacy of cognitive-behavioral and family interventions for adolescent substance use disorders (SUD), HIV-risk behaviors, and related problems. Despite support for these interventions, substantial heterogeneity in treatment outcomes and high relapse rates has been consistently found across studies. Such variability highlights the need for innovative strategies to broaden the impact and strengthen the durability of effects of adolescent substance abuse treatments. Research has demonstrated the positive effects of contingency management (CM) methods on reductions in substance use, primarily with adults. CM has been shown to improve outcomes when combined with evidence-based practices and research is emerging to suggest that such integrations may also be effective for adolescent substance abusers. The proposed Stage II efficacy trial examines the integration of CM with two empirically- supported interventions: group MET/CBT and FFT. By comparing two intervention modalities (group vs. family), the study provides a unique opportunity to examine the robustness of the effects of CM across established adolescent treatments that are widely implemented in community settings, and to compare change mechanisms that may account for treatment outcomes. In the proposed research, substance abusing adolescents (n = 160) will be randomly assigned one of four intervention conditions, two with an integrated CM intervention (MET/CBT-CM, FFT-CM) and two without CM (MET/CBT, FFT). The study will employ a 2 (Incentives: CM, noncom) x 2 (Modality: MET/CBT, FFT) x 5 (Time: Baseline, 2-, 4-, 8-, and 12-months post- randomization) factorial design. The primary aim of the study is to examine the efficacy of an integrated CM intervention, FFT-CM and group MET/CBT-CM, compared to these treatments without CM on drug abuse abstinence (a) during treatment (i.e., speed of effects) and (b) at post-treatment follow-up assessments (i.e., durability of effects). A second aims is to examine the impact of interventions on adolescent sexually risky behavior and conduct problems. A third aim is to evaluate the effects of CM on hypothesized mediators of intervention effects. We anticipate that the CM conditions, compared to the noncom conditions, are more likely to accelerate the adolescent's motivation to achieve abstinence, to attend and participate in treatment, and to complete homework assignments. Additional exploratory analyses will examine differences between modalities (MET/CBT vs. FFT) on the presumed mediators: MET/CBT will produce greater improvements in adolescents drug avoidance self-efficacy and FFT will produce greater improvements in family relationships (as measured by the FES). Improvements in drug avoidance self-efficacy and family relationships will mediate improvements in MET/CBT and FFT, respectively. Finally, we will conduct an informal cost-effectiveness analysis to derive preliminary estimates of the relative costs of each treatment modality, particularly with respect t treatment engagement/attendance and youth outplacement to restricted settings. PUBLIC HEALTH RELEVANCE: Evidence-based treatments for adolescent substance abuse are successful for some adolescents but not others, with uneven maintenance of gains for those who improve. The proposed clinical trial is designed to broaden the impact and strengthen the durability of effects of adolescent treatments through the use of motivational incentives to accelerate sobriety efforts and other behavioral changes. Integrating contingencies into family-based and cognitive behavioral therapies, the two most common empirically supported interventions for adolescent substance abuse, will ensure that study findings are relevant to the largest segment of adolescent treatment providers.